Yeah, I also prefer singel player in NSMB. Wii, because most of the people I know are rather unexperienced in 2d-Sidescrollers, while more experienced in the First-Peson-Shooter genre. Some Levels within the game is basically not fit for the game. I have always thought that the game is developed as a singel-player game but with an addition of multiplayer.
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3DS Friend Code: 4553 - 9954 - 4854. Name - David